1. Field of the Invention
The invention pertains to epicyclic gear systems and driving means therefor, capable of use as motors, pumps, or engines or drive means for pumps or other machines.
2. Description of the Prior Art
Epicyclic gear systems comprising at least three planetary gears, with a primary planetary gear mounted on an eccentric fixed on a drive shaft and meshed with other two peripheral planetary gears which in turn are in mesh with a peripherally located stationary ring gear are known to the art.
In recent years, the use of an epicyclic gear system for fluid pumps or motors has been contemplated. In British Pat. No. 1,158,638 (dated July 16, 1969) to John Arthur Halliwell and David Eric Turnbull, such a system was described and claimed. In that system, three planetary gears are disposed within a sealed compartment to form two separate volumes for processing of fluid flow into and out of the system. A primary planetary gear is mounted on an eccentric fixed on a drive shaft at a selected distance away from the center of a surrounding stationary ring gear, which meshes with the peripheral planetary gears, the latter also meshing with the primary planetary gear. The system is driven through rotation of the rotor, which displaces the central planetary gear causing it to rotate against the peripheral planetary gears which in turn rotate against the peripheral ring gear. Operation of the existing system has proven unsatisfactory due to the fact that in the "dead center position", i.e. a position in which the three planetary gears are disposed in a straight line, the motion is undetermined and the system tends to jam. This constitutes a serious drawback to the feasibility and usefulness of the device. Various expedients which have been attempted to obviate the problem of jamming have hitherto proven unsatisfactory.
Therefore, there has been a felt but unfulfilled need for an epicyclic gear system capable of use as a pump, a motor, or an engine or drive for pumps or other machines which functions smoothly and consistently, without jamming at any point of its operation and, in particular, at its dead center position.